Dynamic stop

ABSTRACT

A dynamic stop for an operator-less, remotely controlled unit carrier system consisting of a pair of stopping bars positioned between the tracks of the carrier system and mounted so that they do not interfere with the passage of the cars of the unit carrier system when not in use, but may be extended into an outward position so that they will contact stopping brackets on the underside of a car which it is desired to stop. The dynamic stop may be mounted on a reciprocating device to absorb the energy of contact.

United States Patent [191 Tresckow et al.

[ DYNAMIC STOP [75] Inventors: Hans-Udo von Tresckow,

Muehlenstrasse, Germany; Calvin R. Davis, Birmingham, Mich.

[73] Assignee: Rexnord Inc., Milwaukee, Wis.

1451 May 28, 1974 FOREIGN PATENTS OR APPLICATIONS 560,387 9/1932 Germany 104/252 Primary Examiner-Robert G. Sheridan Assistant Examiner-l enneth Noland Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [5 7] ABSTRACT A dynamic stop for an operator-less, remotely controlled unit carrier system consisting of a pair of stopping bars positioned between the tracks of the carrier system and mounted so that they do not interfere with the passage of the cars of the unit carrier system when not in use, but may be extended into an outward position so that they will contact stopping brackets on the underside of a car which it is desired to stop. The dynamic stop may be mounted on a reciprocating device to absorb the energy of contact.

3 Claims, 3 Drawing Figures SHEET 1 (IF 2 PATENTEDmza I974 $812,790 SHEET 2 OF 2 ATENTEBMAY 2a 1914 DYNAMIC STOP FIELD OF THE INVENTION The invention relates generally to the selective stopping of cars in an operatorless, railway type transpon tation system and, more specifically, to the stopping of operator-less, remotely controlled cars in a transportation system such as is disclosed in commonly assigned US. Pat. Nos. 3,621,790, 3,626,859, and 3,650,216.

BACKGROUND OF THE INVENTION To meet the demands of some transportation systems, it is necessary or desirable to use a large number of small cars, or carriers, rather than a few large carriers, or trucks. This is particularly true when the freight to be carried by the transportation system must be sent to a large number of different destinations, but promptness is required, so that it is not feasible to accumulate to any great extent different loads going to a common destination. Such systems, moreover, may be extremely heavily trafficked, as where they are used for baggage transportation in a major airport or mail transportation in a large post office. In such situations, it is necessary that mechanism be provided to permit rapid, selective stopping of the cars in the transportation system. This stopping may be required, for instance, before switching points, in idle car storage areas, and before car elevators and turn-tables. Such a mechanism is disclosed in general terms, but not claimed, in commonly assigned U.S. Pat. No. 3,626,859.

SUMMARY OF THE INVENTION The cars of an operator-less unit carrier system may be rapidly and selectively stopped by means of a pair of stopping bars positioned between the tracks of the carrier system and mounted so that they do not interfere with the passage of the cars of the unit carrier system when not in use, but may be extended into an outward position so that they will contact stopping brackets on the underside of a car which it is desired to stop. In a further refinement of the present invention, the stop may be mounted on a reciprocating device, the actuation of which on contact with the car absorbs the energy of the contact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1.

FIG. 3 is a front view of the dynamic stop shown in 7 FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment of this invention, two stopping bars 10 are slidably mounted in guides 11 and 12. The inside ends of the stopping bars 10 are pivotably connected to link bars 13, which are in turn pivotably connected to double clevis 14. The double clevis 14 is fixedly connected to a double-action air cylinder 15, and the air cylinder 15 and the guides 11 and 12 are all mounted on recoil bracket 16. This configuration permits the stopping bars 10 to be extended by the operation of the cylinder 15 into the path of stopping brackets (not shown) mounted on the underside of the cars (not shown) of the unit carrier system. The stopping brackets can be of any appropriate design, the only requirement being that they be a part of or solidly connected to the cars in a position to be contacted by the stopping bars 10 when in their extended position.

The recoil bracket 16 is mounted on the front of a reciprocating denoted generally by the number 17 assembly, (see FIG. 2). This reciprocating 17 consists essentially of a centrally positioned shock absorber 18, a pair of spaced compression springs 19, connecting and bracing elements (including, of course, the recoil bracket 16), and guides to control the path of the reciprocation. One suitable mechanism for controlling the path of reciprocation are the cam followers 20 and 21, which limit, respectively, the lateral and vertical movement of the reciprocating device, and the sliding element 22, which may be attached either to the stationary frame 23 or the recoil bracket 16. The cam follower 20 is mounted directly on the recoil bracket 16, and the cam follower 21 is mounted on an angle iron 24, which permits the cam follower 21 to engage the under surface of the frame 23. The stationary frame 23 and the may be atttached directly to ground, or, as shown, it may be attached to the rails 25, which are in .turn attached to ground in a manner not shown. This configuration permits the shock absorber 18 to absorb the energy of contact, while the compression springs 19 (and, if the shock absorber is, as shown, a resilient device, its internal return mechanism) are present to return the reciprocating device (and, via the stopping arms 10, the stopped car) to its position at initial contact with the car. For that reason, the compression springs 19 and, if present, the internal return mechanism in the shock absorber must be strong enough to move the weight of the reciprocating device 17, the stopping bars 10 and their ancillary elements, and the car, as well as to simultaneously overcome the forward motivating force of the stopped car, as will be explained in the next paragraph.

The operation of the air cylinder 15 may be controlled by any appropriate means for example, the mechanism disclosed in commonly assigned US. Pat. No. 3,626,859. Such control permits the selective stopping of the cars of the unit carrier system and moreover, permits the precise positioning of the stopped cars, which may be held in place against the stopping bars 10 after they have been brought to a halt by maintaining the forward motivating force of the cars at a very low level while they are stopped. This ability to precisely position the stopped cars is very important in minimizing the merging space needed between the cars on a main line when the present invention is used in a queingsystem such as is disclosed in commonly assigned U.S. Pat. No. 3,626,859.

CAVEAT While the present invention has been illustrated by a detailed description of the presently preferred embodiment thereof, it will be readily appreciated by those skilled in the art that various modifications in form and detail can be made therein without departing from the scope of the inventive concept. For this reason, the scope of the invention must be measured by the appended claims and not by the preferred embodiment disclosed herein.

What is claimed is:

l. A dynamic stop for selectively stopping the cars of a unit carrier system having a plurality of cars which travel along tracks, said stop comprising:

I a stationary frame adapted to be mounted adjacent to said tracks;

2. a recoil bracket slidably mounted on said stationary frame in a manner permitting said recoil bracket to move in the direction of and counter to the direction of travel of said cars on said tracks when said stationary frame is mounted adjacent to said tracks;

3. a shock absorber mounted on said stationary frame in a manner permitting said shock absorber to oppose the motion of said recoil bracket in the direction of travel of said cars on said tracks;

4. means for biasing said recoil bracket in the direction counter to the direction of travel of said cars on said track;

5. a double-action fluid cylinder mounted on said recoil bracket;

6. a double clevis fixedly connected to the piston of said double action fluid cylinder;

2. A dynamic stop as recited in claim 1 wherein said stationary frame is adapted to be mounted between two parallel tracks and said dynamic stop further comprises guide means for controlling the path of reciprocation of said reciprocating assembly.

3. A dynamic stop as recited in claim 1 wherein said means for biasing said recoil bracket comprise a compression spring operatively disposed between said stationary frame and said recoil bracket. 

1. A dynamic stop for selectively stopping the cars of a unit carrier system having a plurality of cars which travel along tracks, said stop comprising:
 1. a stationary frame adapted to be mounted adjacent to said tracks;
 2. a recoil bracket slidably mounted on said stationary frame in a manner permitting said recoil bracket to move in the direction of and counter to the direction of travel of said cars on said tracks when said stationary frame is mounted adjacent to said tracks;
 3. a shock absorber mounted on said stationary frame in a manner permitting said shock absorber to oppose the motion of said recoil bracket in the direction of travel of said cars on said tracks;
 4. means for biasing said recoil bracket in the direction counter to the direction of travel of said cars on said track;
 5. a double-action fluid cylinder mounted on said recoil bracket;
 6. a double clevis fixedly connected to the piston of said double-action fluid cylinder;
 7. a link bar pivotably connected to said double clevis at either end thereof; and
 8. a stopping bar pivotably connected to each of said link bars at the end thereof remote from said double clevis, said stopping bars being slidably mounted on said recoil bracket in a plane generally perpendicular to the direction of travel of said cars on said track and in a location where they do not interfere with the passage of said cars when retracted, but will contact said cars when extended.
 2. a recoil bracket slidably mounted on said stationary frame in a manner permitting said recoil bracket to move in the direction of and counter to the direction of travel of said cars on said tracks when said stationary frame is mounted adjacent to said tracks;
 2. A dynamic stop as recited in claim 1 wherein said stationary frame is adapted to be mounted between two parallel tracks and said dynamic stop further comprises guide means for controlling the path of reciprocation of said reciprocating assembly.
 3. A dynamic stop as recited in claim 1 wherein said means for biasing said recoil bracket comprise a compression spring operatively disposed between said stationary frame and said recoil bracket.
 3. a shock absorber mounted on said stationary frame in a manner permitting said shock absorber to oppose the motion of said recoil bracket in the direction of travel of said cars on said tracks;
 4. means for biasing said recoil bracket in the direction counter to the direction of travel of said cars on said track;
 5. a double-action fluid cylinder mounted on said recoil bracket;
 6. a double clevis fixedly connected to the piston of said double-action fluid cylinder;
 7. a link bar pivotably connected to said double clevis at either end thereof; and
 8. a stopping bar pivotably connected to each of said link bars at the end thereof remote from said double clevis, said stopping bars being slidably mounted on said recoil bracket in a plane generally perpendicular to the direction of travel of said cars on said track and in a location where they do not interfere with the passage of said cars when retracted, but will contact said cars when extended. 